Not true at all, it does happen in real life. As a child, I use to joke to my parents "If I become rich, and I still like Carls Jr (a fast food joint over here), am I still allowed to go eat there?". Then come adulthood.... yah, if you want carls jr as a millionaire, you go get carls jr!
Of course, that's not what you mean by a millionaire TALKING to a burger flipper. However, it's very much possible in more academic settings. That's what I love about socializing with colleagues and scientists, everyone loves what they're doing and sometimes you're talking to someone who has a hall named after him at a University and you'd never know it.
Statistically, there are a number of millionaires on this board most likely. I sure as hell am not one, according to the university I get a bit over minimum wage ($11 or so) but I'm on contract. I don't think many rich people will out themselves, however. Hell, girls have problems with guys? Make some money and see how much unwanted attention you get!